Electric-arc lamp.



No. 678,058. Patented luly 9, IBM. 6. P. STEINMETZ.

ELEGTRIG ARC LAMP.

(Application filed Apr. 8, 1901.)

(No Model.)

Fig.1.

Fig.2.

\Nicnesses. lnvrsniior'. W Charles 1 .55 inmet;

THE Nonms PETcRs' :c. PNOTQ-LITHO WASHINGTON u. c.

CHARLES P. STEINMETZ, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, OF NEW YORK.

ELECTRIC-ARC LAM P.

SPEQIFILGATTON forming part of Letters Patent No. 678,058, dated July 9, 1901.

Application filed April 8, 1901. Serial No. 54,869. (No model.)

T0 at whom it may concern:

Be it known that I, CHARLEs P. STEIN- METZ, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric-Arc Lamps, (Case No. 1,479,) of which the following is a specification.

One of the objects of my present invention has been to produce an arc-lamp in which the arc regnlating mechanism is caused to respond promptly and vigorously to any change or tendency to change of current passing through the are. This sensitiveness of the arc-regulating mechanism enables me to dis pense either wholly or almost entirely with external resistance or other devices for securing stability of operation of the lamp. The means whereby I secure this result may briefly be described as comprising a plurality of coils acting upon the regulating mechanism of the lamp, one of these coilsas, for example, that one which serves to separate the carbons-being opposed by another one of the coils, the resulting action upon the mechanism being therefore due to a differential effect. The coil which serves to separate the carbons I will term for convenience the main coil, and in this coil Icause current to vary at a rate different from the rate of variation of current in the other coil, which for convenience I will term the differential coil. The effect of a fluctuation of current in the arc is to cause the resultant action of the regulating-coils upon the arc-controlling mechanism'to vary at a greater rate than the rate of variation of current in the arc,thereby temporarily magnifying and rendering more vigorous the action of the arcregulating mechanism.

In the drawings, Figure 1 represents in diagram one embodiment of my invention, and Fig. 2 a modified form of the same.

Referring to Fig. 1, the part numbered 1 represents the core of a pair of solenoids 2, this core being operatively connected in any ordinary manneras, for example, through the clutch 3-with the carbon or other electrode 4. The cooperating carbon or electrode is indicated at 5. The solenoids 2, with which the core 1 cooperates, are provided The main Winding 6 is so arranged that upon the occurrence of a variation of current in the are there will be alarger proportionate, although temporary, change of cur rent in the said main winding. The differential winding 7 is arranged so that the current therein varies either at the same rate as the Variation of current in the arc or at a slower rate, as may be desired. The connections whereby these results are secured may differ considerably without departing from the spirit of my invention. One of the means foraccomplishingthe resultis,however,shown in Fig. 1, and consists in dividing the main circuit as it enters the lamp at 8 into two branches, one of which (indicated at 9) passes through the main coil 6, and the other branch (indicated at 10) passes through an inductance or kicking coil 11, then through the reversely-wound or differential coil 7, and joins the other branch 9 at some point, as 12, from which the circuit continues through the carbons 4. 5 and out to the other terminal of the lamp, (indicated at 13.)

The branch 9, including the main coil 6, is proportioned so as to have a higher resistance than the branch 10, the latter branch, on the other hand, being caused, principally by the use of theinductance-coil 11, to have a higher self induction than the first mentioned branch. Any means other than that described for securing a difference between the time constants of these two branch circuits is of course well within my invention.

Suppose, for example, a sudden increase of current occurs in the are due perhaps to a sudden wasting away of particles of carbon. Then owing to the difference in time constants of the two branch circuits 9 and 10 the current through the main coil 6 will increase at a higher rate than that through the arc, while that in the differential coil 7 will increase slower. While these changes are going on the pull exerted by the differential action of the solenoids 2 upon the core 1 will be temporarily increased in an almost impulsive manner, the pull on the core rising rapidly at first and then declining as the current reaches a steady value. A decrease of current through the arc of course has an exactly opposite effect, the sustaining force of the solenoids being temporarily decreased in a proportion considerably greater than the decrease of current in the arc, thereby allowing a rapid readjustment of the electrodes by driving the current back to its normal value.

Fig. 2, which represents the modified form of my invention, differs from Fig. 1 only in that the differential coil 7 instead of being connected in series with the inductance-coil 11 is connected directly in series with the main line 8. This connection, while in some respects not as advantageous as that shown in Fig. 1, is, however, nevertheless highly useful and constitutes one of the embodiments which my invention may assume.

The mode of operation will be readily understood from the explanation above given, it being only necessary to add that the effect of the diiferential coil 7 instead of varying slower than the variation of the current in What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In an electric-arc lamp, the combination of differentially-acting coils connected so as to respond with different degrees of promptness to variation of current in the arc, and arc-regulating mechanism operatively related to said coils.

2. In an electric-arc lamp, the combination of branch circuits of different time constants, coils connected respectively in said branch circuits, and arc-regulating mechanism operatively related to said coils.

3. In an electric-arc lamp the combination of arc-regulating mechanism operated on by differentiallyacting coils, and branch circuits of different time constants into which said coils are respectively connected.

4. In an electric-arc lamp, the combination of branch circuits of different time constants, said branch circuits including a main coil or winding in one of said branches and a dif= ferential coil in another bran ch, and area-egalating mechanism operatively related to said coils.

5. In an electric-arc lamp, the combination of branch circuits a main coil or winding in one of said branches, a ditferential coil and an inductance-coil in another branch circuit, and arc-regulati n g mechanism operatively related to said coils.

In witness whereof I have hereunto set my hand this 5th day of April, 1901.

CHARLES P. STEINMETZ.

\Vitnesses:

BENJAMIN 13. HULL, FRED Ross. 

